ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2019
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IF 7.149
Jiexu Ye,Chenkai Jiang,Han Chen,Yao Shen,Shihan Zhang,Lidong Wang,Jianmeng Chen
The biphasic solvent-based absorption process has been regarded as a promising alternative to the monoethanolamine (MEA)-based process because of its high absorption capacity, phase separation behavior, and potential for conserving energy for CO2 capture. A trade-off between the absorption capacity and phase separation ratio is critical for developing an advanced biphasic solvent. Typically, water content in the biphasic solvent can be manipulated to tune the phase separation behavior. To explore the relationship between water content and phase separation behavior, an inert organic solvent, 1-methyl-2-pyrrolidinone, was added as a substitute for water in a biphasic solvent, specifically a triethylenetetramine (TETA) and 2-(diethylamino)ethanol (DEEA) blend. Moreover, the water content−kinetics and thermodynamics relationships were also evaluated. Experimental results revealed that reducing the water content was beneficial for phase separation but adverse for adsorption capacity. Kinetic analysis indicated that the water content did not significantly affect the rate of CO2 absorption at a rich loading. Furthermore, the regeneration heat decreased with the water content. The regeneration heat of TETA–DEEA with a water content of 20 wt % was almost 50% less than that of MEA solution. 13C nuclear magnetic resonance analysis revealed that the water content did not affect the reaction mechanism between CO2 and amines.
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PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 136
·期 46
·48237
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IF 2.188
Feng Gao,Yifang Mi,Xinlei Wu,Jun Yao,Qi Qi,Zhihai Cao
Stimuli-responsive polymeric nanogels hold great potential in biological applications. In this work, thermoresponsive polymeric nanogels were conveniently prepared through inverse miniemulsion polymerization of two monomers with a good biocompatibility, N -vinylcaprolactam and 2-methoxyethyl acrylate. A macromolecular crosslinker, poly(ethylene glycol) dimethacrylate (PEGDMA), was used to achieve a better thermoresponsiveness, compared with low-molecular-weight crosslinkers. The prepared poly( N -vinylcaprolactam- co -2-methoxyethyl acrylate) (poly(NVCL- co -MEA)) nanogels could be well redispersed in aqueous systems, displaying a reversible thermoresponsive transition behavior. The influences of the synthesis parameters including the emulsifier content, PEGDMA content, and monomer composition on the particle properties of poly(NVCL- co -MEA) nanogels both in inverse emulsions and in aqueous dispersions were systematically investigated. Furthermore, the impacts of the monomer composition and PEGDMA content on the thermoresponsiveness of poly(NVCL- co -MEA) nanogels were also studied. Promisingly, the introduction of MEA monomeric units to the copolymer chains only slightly reduced the thermoresponsiveness of poly(NVCL- co -MEA) nanogels. This feature allows to improve the biocompatibility of polymeric nanogels by using MEA as the comonomer without need to compromise the thermoresponsiveness of nanogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48237.
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高影响因子
APPLIED SURFACE SCIENCE
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2019
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IF 5.155
Ya Wang,Zhiqiang Fang,Qingsong Dong,Yiyue Chu,Xiaoyu Shi,Mingxing Song,Zhaomin Hao
Nickel sulfides have been considered to be among the most effective oxygen evolution reaction (OER) electrocatalysts . Until now, there are many different nickel sulfides, such as Ni 3 S 2 , NiS, Ni 3 S 4 , NiS 2 , etc. In this paper, we set out to explore the influence of the S:Ni ratio in raw materials on the different nickel sulfides. With the characterizations of XRD , XPS , SEM, TEM and BET, the relevance between the molar ratio of S:Ni in raw materials and stoichiometric ratio, microscopic structure and OER performance are discussed. According to the results of the experiments, the Ni 3 S 4 derived from the 3:1 M ratio of S:Ni in raw material exhibits the smallest overpotential (245 and 314 mV to achieve 10 and 20 mA/cm 2 ) and Tafel slope (81.5 mV/dec). Meanwhile, theoretical calculation of ΔG(H 2 O*) indicate that the adsorption energy in Ni 3 S 4 is much closer to the IrO 2 than other nickel sulfides, which are in good agreement with the OER performance of electrochemical measurements.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2019
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IF 5.107
Yifu Li,Li'ao Wang,Zhongchao Tan,Zhien Zhang,Xinyue Hu
Absorption and desorption of CO 2 using K 2 CO 3 solutions promoted by three amino acid salts (AASs), potassium glycinate (PG), potassium lysinate (PL) and potassium L-argininate (PA), were evaluated using 40% CO 2 at 40 °C and with pure N 2 at 80 °C, respectively. The addition of all 3 AASs clearly enhanced both absorption and desorption of CO 2 compared to single K 2 CO 3 solution. PA + K 2 CO 3 solution showed the highest CO 2 cyclic capacity of 0.678 mol CO 2 /mol absorbent, while the highest CO 2 absorption and desorption rates of 39.8 and 17.6 mol CO 2 L −1 s −1 were achieved by PG + K 2 CO 3 solution. Finally, simulated biogas containing 40% of CO 2 and 60% of CH 4 was used as test gas in a hollow fiber membrane contactor. PG and PA promoters presented higher CO 2 absorption flux and removal efficiency than PL promoters in K 2 CO 3 solution within low Gas/Liquid ratio region. Stable CO 2 removal performances for all three promoters were observed at elevated temperature and pressure for 60 min operation.
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高影响因子
APPLIED ENERGY
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2019
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IF 8.426
Xiaowen Zhang,Yufei Huang,Hongxia Gao,Xiao Luo,Zhiwu Liang,Paitoon Tontiwachwuthikul
The extensive energy penalty of CO 2 -loaded solution regeneration is one of the most crucial challenges facing industrial application of amine-based CO 2 capture technology. Here, to decrease the energy requirement, the regeneration behaviors of the rich 5 M monoethanolamine (MEA) and 3 M MEA-2.5 M N-methyl-diethanolamine (MDEA)−0.5 M piperazine (PZ) tri-solvent blended amines (tri-blend) with four different solid acid catalysts (H-mordenite, Hβ, HZSM-5 and Al 2 O 3 ) were studied at 98 °C. For the catalyst-free tests, the results revealed that the tri-blend hugely enhanced the CO 2 desorption kinetics and reduced the relative energy consumption compared to 5 M MEA. Based on the results of 13 C NMR, the multiple proton transfer paths and abundant bicarbonate ions in the tri-blend contribute to the improved regeneration performance. Additionally, the use of catalyst further improved the CO 2 desorption activity of the tri-blend. The combination of Hβ and tri-blend presented the best regeneration performance, increasing the desorption performance by 1360.8%, and reducing the relative energy requirement by 66.1% compared with the blank run of MEA. In addition, a plausible catalytic mechanism of solvent regeneration over the solid acid catalyst in the tri-blend was suggested. The superior catalytic performance of Hβ resulted from the large mesoporous surface area, larger number of Brϕnsted acid sites and prominent total acid sites. Furthermore, Hβ displayed excellent stability and had no adverse influence on the CO 2 absorption activity. Results herein manifest that the combination of tri-blend amines with high-efficiency catalyst is exceptional strategy for tremendously decreasing the energy consumption of amine-based CO 2 capture processes, ultimately making this technology more technically and economically feasible.
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高影响因子
APPLIED ENERGY
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2019
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IF 8.426
Hui Guo,Chenxu Li,Xiaoqin Shi,Hui Li,Shufeng Shen
High energy consumption for CO 2 capture using aqueous amines is still a major drawback limiting its deployment on a global scale. In this work, the absorption-desorption performance of CO 2 into several blends of monoethanolamine (MEA) or diethanolamine (DEA) with glycol ethers (2-methoxyethanol (2ME) and 2-ethoxyethanol (2EE)) as nonaqueous solvents has been investigated at ambient pressure. Reaction mechanisms and the relative heat duty for these nonaqueous systems were also explored and compared with those of the aqueous MEA. Results showed that the nonaqueous absorbents with 5.0 M MEA had comparable absorption capacity with aqueous 5.0 M MEA and higher desorption efficiency resulting in a larger cyclic capacity (1.45 mol kg −1 ). Higher partial pressure ratio of CO 2 to solvent vapor under the desorption conditions was also observed for these nonaqueous systems. 13 C NMR, FTIR spectra and online conductivity analysis provided evidences that CO 2 can react with MEA in nonaqueous solvents forming the ionic couples (i.e. protonated MEA and carbamate) as well as carbamic acid at high CO 2 loading. The mixture of MEA and 2ME or 2EE could significantly reduce the energy consumption by about 55% as compared to the benchmark aqueous 5.0 M MEA system.
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高影响因子